HC Deb 28 July 1966 vol 732 cc2055-64

Motion made, and Question proposed, That this House do now adjourn.—[Mr. Fitch.]

11.20 p.m.

Mr. Anthony Kitson (Richmond, Yorks)

In a week when we have had the announcement of a brucellosis eradication scheme, for which many hon. Members on this side of the House have been pressing over a number of years, it is almost unfair to launch into debate about another disease which is similar in that salmonella typhimurium can affect the human being through a disease in cattle. It is probably true to say that the dangers to humans are going to be far greater unless precautions are taken immediately to counter the spread of this disease in cattle.

Already this year we have had confirmed in the Portsmouth area—and I have established this with the public health laboratory there—the deaths of three people from salmonella typhimurium. My attention was first drawn to this problem by a series of excellent articles, written by John Field, in the Reading Evening Post. I felt it right to check the factual content of these articles and this led me to some documents upon which these articles were based and which have been produced by Dr. Anderson, who is the Director of the Central Public Health Laboratory. He has been doing research work on this problem for several years and in conjunction with Dr. Lewis he has produced a number of papers.

Salmonella typhimurium is the commonest cause of food poisoning in the country. It affects about a thousand people a week, and it is an unpleasant disease which is more liable to kill the very young or very old. It would appear from medical reports that it is on the increase. It is also the commonest cause of calf death in this country. Since large numbers of calves are reared for human consumption the dangers of transmission of this disease from meat to humans is obvious. It is an accepted medical fact that bacterial resistances to any given drug is fostered by continual administration of that drug and that the use of drugs in animal husbandry over the last 10 years has increased rapidly.

This has prompted Anderson and Lewis, in an article in the British Medical Journal, to point out that the high incidence of drug resistance in calves was due to a combination of poor hygienic conditions in animal husbandry, especially in intensive farming, transport and marketing of calves and the distribution of infected stock by dealers, and by the too free use of anti-bacterial drugs in efforts to control the resultant salmonellosis.

Drug resistance is usually multiple and is directed against the anti-bacterial drugs commonly used in human and veterinary medicine, for example, ampicillin, chloramphenicol, neomycin, kanamycin, streptomycin, sulpholomides and tetracycline. Therefore, if a farmer has a drug resistant salmonella in his herd the drugs to which the salmonella is resistant will have no effect on anyone contracting that salmonella, that is the drug resistant one.

There are no enforceable restrictions to stop a farmer who has a drug resistant salmonella in his herd from selling his animals and spreading the disease, and therefore the resistant organisms. There is documentary evidence that a particular salmonella has been spread by one calf dealer into nearly every county—certainly into 37 counties. Even though the technical laboratories and the public health workers know the background to this problem there are no powers to control it.

This brings me back to the three deaths in the Portsmouth area. In a recent outbreak in Hampshire five deaths occurred, three of which were from a salmonella typhimurium infection. The strain was of the type 29, which is most commonly found in calves and certainly resistant to several antibiotics. Three of those who died were children and there were no inquests. The causes of the deaths were septicaemia in two cases and salmonella meningitis in the third. All began with an initial infection of salmonella typhimurium. Eight of those not fatally infected were very seriously ill, and detailed evidence points strongly to calves being responsible. The figures were confirmed by Dr. Payne of the Portsmouth Public Health Laboratories. He pointed out that this was an area which had been relatively free from salmonella in the past.

I should like to draw the attention of the Parliamentary Secretary to an article which was produced by Dr. Geoghagan in The Medical Officer of Health. He is the medical officer for the Midhurst Rural District. The article said: In a well documented case of food poisoning 59 people in West Sussex were hit by Salmonella Typhimurium in their milk last April—the source of the infection was a herd of calves in an intensive beef unit on the same farm as the dairy herd. The intensive beef unit was set up as a sideline by the dairy farmer, using very young calves bought from a dealer 100 miles away specialising in the calf trade.

Over a dozen beef calves were housed in separate buildings some distance from the dairy herd. Within days one of the calves died and Salmonella was confirmed. The area medical officer, Dr. V. P. Geoghagan, was immediately informed though it was not yet directly his concern.

But a matter of days later he was called in by a woman whose children, aged six and 18 months, had gastro-enteritis. Though a check on milk from the farm—which was sold unpasteurised—proved negative for Salmonella, cultures from the dead calf and sick children showed Salmonella Typhimurium of the same type—phage 29.

The farmer was contacted but he maintained that since the beef calves and the dairy herd were separately housed the infection could not have spread.

Inside a week five more cases were reported, even though the farmer had agreed to pasteurise all his milk while samples were tested for Salmonella. One of the five cases was a contact with the first sick children.

By April 29 nine beef calves had died, one milking cow had died and other cows were showing signs of infection. Reports of infection were flowing in from local doctors and a total of 59 cases of poisoning were recorded. Many were hospital cases.

Salmonella was eventually confirmed in the milk and an order made for the farmer to pasteurise his milk compulsorily until the infection was cleared.

Although he wound up his beef unit the farmer's cows were not cleared by the authorities until November. Cost of the whole disastrous beef rearing operation—ten beef calves, one dairy calf, a dairy cow and six months' lost profit on milk sales plus 59 cases of poisoning, some requiring hospital treatment."

Dr. Geoghagan's report on the outbreak went on: Several lessons have been learned from the outbreak. Salmonellosis in cattle is not covered by the Diseases of Cattle Acts, so even when it is detected in a dairy herd or on a dairy farm the medical officer of health would not necessarily know about it. Indeed, there is no obligation for the Divisional Veterinary Surgeon to be informed. The most frustrating aspect of Salmonellosis in cattle is that having detected the infection and having prevented its spread to the public via milk one has no power to eradicate the disease from the herd concerned. These figures demonstrate the necessity for the Ministry of Agriculture to take powers immediately.

I recognise that a Committee under Lord Netherthorpe was set up to look into the problems of the use of drugs in animal husbandry and the use of antibiotics as feed additives, and I would hope that, when the Parliamentary Secretary replies, he will indicate whether the terms of reference of that Committee would enable it to consider some of these problems. Of course, this does not detract from the necessity for the Minister to take powers to cope with the situation as we have it today.

The Report of the Netherthorpe Committee, which was submitted to the Agriculture Research Council and the Medical Research Council in 1962, pointed out that the dangers of the use of antibiotics in animal husbandry should be watched, and rapid action should be taken by the authorities concerned with control. But it would appear to me that the Minister of Agriculture has no control.

There is little doubt that there should be better liaison between the Ministry of Health and the Ministry of Agriculture about the problem. I have stressed before, when campaigning over the problem of paratyphoid B and the importation of liquid Chinese egg, the problems of brucellosis and the human infection through undulant fever and again this problem of salmonella typhimurium diseases, the necessity for a more coordinated approach to the problem between the two Departments.

There is no doubt that the build up of drug resistant organisms, both in animals and in human beings, will increase unless a firm approach is made to the problem. Only too often before have I seen the findings of eminent research workers in these fields, when recommendations and papers have been produced, being shelved for future consideration, and the British Medical Association and the British Veterinary Association have supported the views of those doing the research that action should be taken immediately.

I hope that the Parliamentary Secretary will have consultations, recognising the importance of the problem, to try to see if powers can be taken by the Ministry of Agriculture so that where we have known cases of salmonella typhimurium on farms, at least his "vets" can go in and clear up the situation. It is an appalling state of affairs when it is known that from one farm the disease has infected 37 counties in the country. I hope that the Parliamentary Secretary will be able to give us some assurances when he replies to the debate.

11.33 p.m.

The Joint Parliamentary Secretary to the Ministry of Agriculture, Fisheries and Food (Mr. James Hoy)

In raising the point about co-operation between Departments, the hon. Member for Richmond, Yorks (Mr. Kitson) does both Departments less than justice. There is a constant interchange of opinions and views on these matters. Indeed, without going too far back, even dealing with antibiotics and the effects which they might have, it may interest the hon. Gentleman to know that, in conjunction with the Ministry of Health, a circular was issued in 1964 dealing with that very subject. It was repeated in the early part of this year, warning all our officials, veterinary officers, veterinary investigation officers and all concerned with the problem to keep a look out for it.

Having said that, I hope that the hon. Gentleman will appreciate that we are very much aware of what is going on. Our veterinary officers will report to medical officers of health cases of salmonellosis in herds if the infection is likely to affect humans. They know that they have to do that.

I do not want to underestimate the seriousness of the problem, but we ought not to create panic over it, because there is no evidence of any increase in the incidence of the disease caused by the organism. Recorded incidents of food poisoning from salmonella typhimurium in England and Wales amongst humans have decreased annually from 2,503 in 1961 to 1,721 in 1965. On the basis of the first five months of 1966, it looks as though there will be a further decline this year. I am sure that the hon. Gentleman will be grateful for that information. No such figures are available for the disease in animals. But reports from our veterinary investigation centres show that, in recent months, the number of cases of salmonellosis confirmed in cattle is considerably lower than for the same period of 1965. The reports also show that the proportion of cases due to salmonella typhimurium has fallen markedly.

Salmonella typhimurium is widespread in nature. It is possible for human beings to be infected from wild animals, and particularly rodents, and from farm animals. It cannot be eradicated, because there is no known way of doing this. I regret having to say it, but that is the fact.

Under suitable conditions, the organism can live away from the animal for a long time, and re-infection from many sources can always occur. Because we cannot take practical action to eradicate it, we have not made the disease notifiable. Carriers showing no symptoms are not uncommon, and a farmer could have the disease on his farm without knowing it. We could, therefore, be faced with the impossible position of prosecuting one farmer for failing to notify a disease which his animals have caught from a neighbour's stock, when we could not possibly take action against the neighbour who had no idea that he was in possession of infected animals.

There is no known treatment which will eliminate carriers. Indeed, some carriers may result from the effective treatment of clinical disease. There is a vaccine against another salmonella, salmonella Dublin. This vaccine has been shown to reduce losses, and to cut the severity of the disease when used against salmonella typhimurium. It is, however, not completely effective.

Antibiotics are used therapeutically, and, in contact stock, prophylactically, at levels which can be dispensed on veterinary prescription only. However, the best way to tackle this problem in cattle is for farmers to adopt measures of good husbandry and hygiene in the planning and execution of their enterprises to prevent the disease appearing.

Gathering calves together in trucks, markets, dealers' premises and the like, increases the chances of cross-infection taking place at a time when they are most susceptible because of the stress associated with this trade and with long journeys. We must remember, however, that without the trade in calves we should have a larger number of calves sold for slaughter as "bobbies" by the farmer who bred them but did not want to rear them, instead of their going eventually to farmers, many miles away in some cases, who will rear them to add to our beef supplies. In any event, a ban on trading in calves would not arrest salmonella typhimurium.

However, effective and fairly simple measures can be taken to lessen the risks. If a single source of calves is available, so much the better. They should have received colostrum soon after birth, they should be at least 10 days old, and they should have been vaccinated before movement. They should be exposed to as little handling, mixing and travel as is possible. Direct farm-to-farm movements are better than purchases via markets.

Good husbandry after arrival should include warm, dry quarters and isolation in small groups away from older calves. Buildings should be planned or modified to ensure that disinfection can be thoroughly and expeditiously carried out.

Similar precautions should be taken for other livestock. Following the 1964 Annual. Price Review veterinary study groups were set up by the National Farmers' Union, the British Veterinary Association and the Ministry's veterinary services throughout the country at regional and county levels to study disease problems and to advise farmers how they can be tackled. These groups have been very active in the past year on the subject of calf losses, including losses from salmonella typhimurium. The Ministry's Veterinary Investigation Service is also available to advise farmers through their veterinary surgeons on particular problems.

I turn now to antibiotics. Some criticism has been made of their use. The problem of what is called "infective drug resistance" has been mentioned. There is no evidence based on field experience to show that this problem is in any material degree due to the use of antibiotics in the treatment of animal disease. It would not, therefore, be right to prevent veterinary surgeons from using these drugs to cure or prevent illness in animals.

Specified antibiotics are scheduled under the Therapeutic Substances Act, 1956, and can be obtained for animal use only on the prescription of a veterinary surgeon, with one exception which I shall mention shortly. We should not curtail the right of veterinary surgeons to use their own judgment in diagnosis and treatment and to use the best methods available to them. We must appreciate that failure to treat disease by the best methods could result in a considerably increased loss in farm livestock; animals would undergo more suffering; and there would be a greater risk of spread to humans. No one would deny the great benefits to agriculture that have resulted from the use of antibiotics. We could consider restricting the use of antibiotics in animals only if there were convincing evidence that human beings would benefit. This evidence does not exist.

I now turn to the exception to this very rigid system of control over antibiotics. Of the specified antibiotics, there are three that may be added at low levels to feed for pigs and poultry. Even so, their use for breeding stock is not allowed. Addition to feed is for the purpose of promoting the growth of the animals, and I must emphasise that this permission is limited to pigs and poultry at very low levels indeed, and is not available for calves.

I am not aware that a connection between this practice and the development of infective drug resistance has been established by field experience. Nevertheless, the possibility has been brought up and is being very closely examined by a joint committee of the A.R.C. and N.R.C. I understand that this committee has reported to these two research councils. We are at the moment awaiting this report. The Ministry's Scientific Advisory Panel is also reviewing the use of antibiotics in food and agriculture. When we have the views of these two advisory bodies we will then consider the matter fully and decide whether any changes in the relevant Regulations are necessary.

I can give the hon. Gentleman the assurance that we do not look on this matter lightly.

Mr. Kitson

Has the Minister any idea when these reports will be available?

Mr. Hoy

As I said, we are awaiting them. I hope that no time will be lost. I do not want to give an exact date, but we hope to receive them quickly.

That is why I was assuring him that when we have them we will lose no time in reaching a conclusion. We do not underestimate this problem. We are grateful to him for raising the matter, because it gives us the opportunity of assuring the public that we are giving it every attention possible.

Question put and agreed to.

Adjourned accordingly at a quarter to Twelve o'clock.